Microwave-assisted synthesis of nano-scale BiVO4 photocatalysts and their excellent visible-light-driven photocatalytic activity for the degradation of ciprofloxacin

New-type synthetic methods of BiVO4 photocatalysts with high visible-light-driven photocatalytic activity are much desired. In this study, the branched BiVO4 nanocrystal photocatalysts were successfully synthesized by a facile microwave-assisted method. They have unique strawberry-like structure with 5 nm sized mastoids scattered on the 200 nm sized particle surface. The obtained photocatalyst exhibits excellent visible-light response (Eg = 2.5 eV) and super-high activities in degradation of ciprofloxacin (CIP). After Pt loading, the photocatalytic activities of branched BiVO4 photocatalysts were enhanced tremendously. Pt nanocrystals on the particle surface not only act as charge collectors and transporters but also produce many active sites. The 2 wt.% Pt loaded BiVO4 nanocrystal photocatalysts exhibit the CIP visible-light-driven photodegradation ratio of 91.97%, which show enhancement of ca. 25% compared with undecorated pure BiVO4 photocatalysts.

• The organic additives-free microwave-assisted synthetic method for BiVO4 photocatalysts was developed. • The as-prepared sample exhibits a unique strawberry-like structure. • The 2 wt.% Pt loaded samples greatly outperform the pure BiVO4 sample in CIP degradation. • A tentative mechanism of charge transfer process in CIP degradation was proposed.